What conditions are needed to grow seedless lychee? Detailed cultivation requirements

In China, lychee generally grows in a subtropical climate. There are many varieties of lychee, including large-seeded, small-seeded, and seedless. Therefore, growers should first understand the varieties of lychee and the taste of each lychee, and then plant reasonably according to market conditions.

Growing conditions for seedless lychee

Because lychee originated in the southern subtropical region of China, and the main producing areas have an annual average temperature of 20-30°C, it has relatively strict temperature requirements, which limits its cultivation distribution. During growth and development it requires high temperature and high humidity, with the most suitable growth temperature being 23-29°C, and growth is slow at 10-12°C. In winter there must be a certain period of appropriately low temperature to help inhibit vegetative growth and promote flower bud differentiation.

In spring, flowering begins only above 10°C, and flowering is most abundant at 18-24°C. Low temperature and rainy weather during the flowering period and young fruit period cause a large amount of flower and fruit drop, and may even lead to total crop failure. Temperatures of 0-2°C will cause low-temperature damage, but mature trees can withstand -2.8°C or even lower temperatures when there is no growth activity. Lychee growth requires sufficient water, with annual rainfall of more than 1200mm required; the main producing areas in South China have annual rainfall of 1500-1800m. Lychee likes light, hence the saying “sunshine lychee”.

According to an analysis of the climate in our city over the past 20 years, it is believed that: generally, January with low temperature (11-15°C), many clear days (12-22 days), long sunshine duration (117h), few rainy days (less than 5-10) days, rainfall of less than 50mm, and relative humidity below 73% indicates a high-yield year. Vigorous growth periods of lychee and the period before fruit harvest should avoid typhoons.

It can adapt to mountain red and yellow soils, flatland sandy loam, alluvial soil, and even clay, but it is best in acidic (PH5-6) sandy loam with deep soil layers, good drainage and irrigation, more than 2% organic matter, loose soil, and the ability to promote root fungus reproduction. The overall requirement is that the long-term vegetative growth period needs sufficient sunlight and plenty of rain, the flower bud differentiation period needs low temperature and dryness, and the fruit development period needs clear weather, with one rain every few days being best.

Construction of a lychee orchard  

1. Choose the orchard site well. For high-yield lychee cultivation, it is ideal to choose hilly land or sloping land with an open terrain, a slope below 30 degrees, loose and fertile soil, and a water source as a development orchard.  

2. Do good planning. For the selected orchard site, carefully carry out variety selection, zoning, roads, drainage and irrigation systems, fertilizer bases, shelterbelts, and auxiliary buildings, so as to facilitate standardized management of the orchard.  

3. Reasonably determine planting density. Generally, in mountainous land, a row spacing and plant spacing of 3.5×3.5 m or 3.5×4 m, with 50-60 plants per mu, is a relatively reasonable density.  

4. Dig large holes and apply sufficient base fertilizer. For orchards reclaimed on hilly land, open contour terrace strips or contour trenches according to the planting row spacing specifications. Then dig planting holes at the selected plant spacing points; the hole specifications are 1 m in length, width, and depth, and each hole should be given 40 kg of composted and decomposed organic fertilizer such as garbage fertilizer, green manure, barnyard manure, and pig and cattle dung as base fertilizer.  

5. Plant carefully. When planting, hold the seedling with one hand and gently backfill fine soil with the other, backfilling to about 2 cm above the roots, water thoroughly to settle the roots, then continue backfilling, and when the backfilled soil is about 10 cm above the ground, form a tree basin, then cover with thatch or stem grass to retain moisture, and set up a support beside the seedling to prevent wind from shaking the seedling loose and causing death. After planting, water once every 3 days on clear days, pay attention to drainage to prevent waterlogging on rainy days, and check survival after 30 days and replant in time.

Flowering characteristics of lychee trees  

The length of the flower bud period from flower spike emergence to before flowering in lychee is related to many factors, but it is most affected by the temperature in winter and spring (January-March), generally 30-40 days, while the length of the flowering period is related to variety, climate, and how early or late the flower spikes emerge; it can be as short as only 15 days or as long as 86 days. Lychee tree flowering has the following characteristics.  

The first is flowering order. Lychee is a tree species with male and female flowers on the same plant but different flowers, with female flowers and male flowers borne on the same flower spike. The flowering order differs according to the position of the flower spike and sex; generally, the single flower between two spikelets opens first, followed by the central flower of each spikelet, and finally the small flowers on both sides. These earlier-opening flowers are mostly male flowers.

When to fertilize lychee  

1. Lychee flower-promoting fertilizer: mainly to enhance tree nutrition before flowering, promote flower bud differentiation, form robust flower spikes, and improve fruit set. The application period for flower-promoting fertilizer is generally 10-20 days before flower bud differentiation.  

2. Lychee fruit-strengthening fertilizer: mainly to supplement the tree nutrient consumption caused by flowering, promote fruit development, promote and strengthen fruit, improve fruit quality, and reduce the second physiological fruit drop. This fertilizer should be applied from after flowering to before the second physiological fruit drop, that is, for early-maturing varieties around Qingming in mid-April, and for late-maturing varieties around Xiaoman in late May.  

3. Lychee shoot-promoting fertilizer: also called post-harvest fertilizer, mainly to supplement the tree nutrient consumption due to fruiting and after harvest, promote tree recovery, and timely sprout autumn shoots to prepare for fruiting the next year. For the application period of this fertilizer, for early-maturing varieties and robust trees it should be after harvest, while for late-maturing varieties, weak trees, and trees bearing many fruits it should be advanced to 10-15 days before harvest.

Before planting lychee, you must first understand the growth habits of lychee, so that you can grow good lychee. For example, in northern China it is certainly not so easy to grow lychee. In fact, mastering some lychee cultivation techniques can greatly improve planting efficiency.